Mercedes-Benz 9G-Tronic transmission


9G-Tronic is Mercedes-Benz's trademark name for its nine-speed automatic transmission, starting off with the W9A 700 as core model.

Abstract

In all applications this transmission is identified as the New Automatic Gearbox Generation Three, or NAG3. Initially it debuted on the E 350 blueTEC in 2013, before launched in the Mercedes-Benz S-Class. It has been expanded to be used in the Mercedes-Benz C-Class and the sedan and wagon variants of the Mercedes-Benz E-Class. This transmission was later introduced on Mercedes-Benz M-Class facelift on the GLE 250 d model. V12 engine models continue to use the older Mercedes-Benz 7G-Tronic transmission. By the end of 2018 unsurpassed ratio span among longitudinal automatic transmissions for passenger cars.
It is also fabricated by Jatco for use in Nissan and Infiniti vehicles.

Specifications

Basic concept

Technical and economic progress is reflected in 9 forward gears out of 10 main components, compared to 7 forward gears out of 11 main components in the direct predecessor. It is fully electronic controlled. Torque converter lock-up can operate in all 9 forward gears.

Gear ratios

Nomogram




This nomogram is a real geometric calculator exactly representing the rotational speeds of the transmission's 3x4 = 12 internal shafts for each of its 9 ratios, grouped according to their 4 permanent coupling on 3 joint ordinates and 5 independent ordinates. These ordinates are positioned on the abscissa in strict accordance with the proportions of the sun gears' teeth numbers relative to those of their rings. Consequently, the output ratios on the 3rd ordinate follows closely those of the actual transmission. This advantageous geometric construction sets us free from famous and tedious formula, because all calculations are exclusively determined by lengths ratios, respectively teeth numbers on the abscissa for the 4 epicyclic ratios, and of rotational speeds on the 3rd ordinate for the 10 gear ratios.
Legend:

A : Brake

B : Brake

C : Brake

D : Clutch

E : Clutch

F : Clutch

Applications

Mercedes models

Mercedes C-Class

Nissan